Ratchet-slide handle and system for fiducial deployment

ABSTRACT

Embodiments include a fiducial deployment system with a handle configured for actuation of same. A fiducial may include one or more protuberances configured to engage one or more slots in a needle of the system. The needle may be configured to deliver a plurality of fiducials to a target location in serial fashion, one at a time. The handle includes an actuation mechanism with a recessible-toothed rack and actuation member(s) configured for incrementally or otherwise controlledly deploying one or more fiducials at a time by advancing a stylet through and/or retracting the body of a slotted needle in which fiducials are disposed with a fiducial protrusion extending into the needle slot, which needle slot also includes retaining structures that do not impede the needle lumen.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.14/180,022, filed Feb. 13, 2014, now U.S. Pat. No. 9,522,264, whichclaims priority to U.S. provisional application Ser. No. 61/769,295,filed Feb. 26, 2013, each of which is incorporated by reference hereinin its entirety.

TECHNICAL FIELD

Embodiments disclosed herein relate generally to a medical device systemincluding one or more fiducials and methods of use for same. Moreparticularly, the disclosed embodiments pertain to handle mechanisms andsystems including same for endoscopically deploying fiducials, andmethods of use for same.

BACKGROUND

Medical procedures often require locating and treating target areaswithin a patient. Focused, dose-delivery radiation therapy requireslocating the target with a high degree of precision to limit damaginghealthy tissue around the target. It is particularly important to knowor estimate the precise location of the target in radiation oncologybecause it is desirable to limit the exposure of adjacent body parts tothe radiation in a patient already suffering the depredations of cancer.However, in all treatment procedures, whether radiologic or otherwise,it is most desirable to be able to accurately target a region to betreated.

In many applications, it is not possible to directly view a treatmenttarget or portion thereof (such as, for example, a cancerous tumor,cyst, pseudocyst, or other target) that needs to be acted on in somemanner. As one example, when treating a lung or pancreatic tumor withradiation, it may not possible to view the actual tumor within thepatient immediately before the radiation treatment. It is thereforehighly advantageous to have some mechanism for permitting the tumor tobe located accurately so that the radiation treatment can be targeted atthe tumor while avoiding damage to healthy tissue.

Even for target regions that may be visualized using CAT(computer-assisted tomography) scans, MRI (magnetic resonance imaging),x-rays, ultrasound, or other techniques, difficulties often arise intargeting a treatment. This is particularly true for target regionswithin a torso of a patient and soft tissue regions. Due to the mobilityof tissues in those regions (e.g., movement of internal organs duringrespiration and/or digestion, the movement of breast tissue with anychange of body position, etc.), a target region may not remain fixedrelative to anatomical landmarks and/or to marks that can be placed ontoan external surface of a patient's body during one of thosevisualization procedures.

Several techniques have been developed to address this problem. One suchtechnique is to place markers into the patient along the margins of thetarget region. The markers may be active (e.g., emitting some kind ofsignal useful in targeting a therapy) or passive (e.g.,non-ferromagnetic metallic markers—called fiducials—that can be used fortargeting under ultrasound, MRI, x-ray, or other targeting techniques,which may be included in a treatment device).

A fiducial is typically formed of a radio-opaque material that thetarget can be effectively located and treated with a device that targetsa site using the fiducials as positional markers under radiographicdetection. Typically, the fiducials may be inserted into the patientduring a simple operation. Percutaneous placement is most commonly used.However, use of minimally-invasive placement via an endoscope hasrecently developed for fiducial placement into a patient's internalorgans. For example, percutaneous placement of fiducials along themargins of a pancreatic tumor can be complex and painful (particularlyfor obese patients, where the needle size is necessarily larger).Another process using percutaneously implanted objects in a patient isbrachytherapy. In brachytherapy, radioactive sources or “seeds” areimplanted into and/or adjacent a tumor to provide a high dose ofradiation to the tumor, but not the healthy tissue surrounding thetumor.

FIGS. 1A and 1B show longitudinal sectional views of a two-pieceintroducer 100 of the prior art useful for placement of brachytherapyseeds or fiducials. Referring first to FIG. 1A, the introducer 100includes a needle 102 and a stylet 104 slidably disposed within theneedle 102. The stylet 104 includes a first handle 101 and a bluntdistal end 106. The needle 102 includes a second handle 103 and abevel-tipped cannula 108 extending through the second handle 103. Thecannula 108 is configured to hold a seed/fiducial 110. The cannula 108has a distal tip 105 configured for percutaneous implantation of theseed/fiducial 110 into the patient.

In a “pre-loaded configuration,” the seed/fiducial 110 is retained inthe cannula 108 by a plug 112 made from bone wax or other suitablebio-compatible material(s). This is typically accomplished by a“muzzle-loading” technique where the fiducial is placed into the distalneedle and then held in place by the bone wax plug. This can presentsome challenges, as the bone wax plug 112 can be visible as an artifactin the patient, potentially interfering with clear visualization of bodystructures or treatment devices. With this configuration, the cannula108 must be withdrawn and reloaded after delivery of each seed/fiducial110. If the target locations for the fiducials are very far apart, useof a single percutaneous introducer cannula/trocar for multipleintroductions of the cannula 108 may not be possible. In such acircumstance, the patient must endure several percutaneous punctures(and the increased attendant risk of infection for each).

To implant the desired arrangement of seeds/fiducials 110 at a targetlocation in a patient, an operator pushes the cannula 108 in a firstdirection (arrow A) to insert the tip 105 into the patient (typicallyunder fluoroscopic visualization). The operator then pushes the secondhandle 103 further in the first direction to position the tip 105 at thedesired depth within the patient where a seed/fiducial 110 is to beimplanted. Throughout this motion, the operator moves the needle 102 andthe stylet 104 together as a unit. At the desired depth/location, theoperator grasps the first handle 101 with one hand and the second handle103 with the other hand. Then, the operator holds the first handle 101stationary while simultaneously sliding the second handle 103 back in asecond direction (arrow B) toward the first handle 101. As shown in FIG.1B, this movement causes the cannula 108 to retract over theseed/fiducial 110 to implant it in the patient. Alternatively, theoperator may move the first handle 101 in the first direction (arrow A)while sliding the second handle 103 back in the second direction (arrowB). This causes the stylet 104 to push the seeds 110 out of the cannula108. The procedure is then repeated to place other seeds/fiducials 110.When being used for targeting of radiation therapy, a minimum of threefiducials is typically required.

As will be appreciated from the disclosed structure, after deploying onefiducial, one may alternatively reload the introducer 100 from theproximal end by completely withdrawing the stylet 104, then placinganother fiducial into the needle lumen and advancing it therethrough toa second location to which the distal needle tip 105 has been directed(a “breech-loading” technique). Provided that the fiducial target sitesare sufficiently close together to allow this technique, it can reducethe number of percutaneous punctures or other access procedures neededto place more than one fiducial. However, it creates a problem forprocedures where ultrasound is being used or is to be used in thenear-future because it introduces air pockets into the tissue andrelated fluids. Those air pockets with tissue and/or fluid are echogenicin a manner that can interfere with ultrasound visualization of a targetarea and/or tools being used to diagnose or treat in/around the area. Insome brachytherapy techniques, a series of fiducials may be preloadedinto the needle—either separately or connected by a suture or similardevice—then placed together in fairly close proximity; however, such atechnique typically is not effective for placing three or more fiducialsin sufficiently disparate locations to use for targeting a treatmentrelative to, for example, margins of a tumor. This may also be true formultifiducial systems that rely upon a distal plug to retain fiducials,which are thereafter released freely, in contrast with systems accordingto the present invention, which are configured for controlled serialrelease (e.g., one at a time, two at a time, or some otheruser-controlled retention and release of a pre-determined number offiducials).

The process is similar when implemented endoscopically in the mannerdeveloped rather recently, except that the needle and stylet are of thetype known in the art for use through the working channel of anendoscope. One limitation of current endoscopic techniques is the sizeof fiducial that can be introduced. With the size limitation ofendoscope working channels, the largest needle that can typically beused without risking bending, crimping, curving or otherwise damaging aneedle (that does not have an internal stylet or other support) duringadvancement out of the endoscope to an anatomical target is a 19-gaugeneedle. This limits the size of the fiducial that can be introducedthrough the needle lumen using current, cylindrical fiducials. Theendoscopic technique generally suffers from the same reloading problemsas described above. Even though the external percutaneous punctures arenot an issue, having to withdraw and reload takes up valuable time andcomplicates the procedure, potentially requiring additional personnel,whether only the stylet is withdrawn for “breech-loading” or the entiredevice is withdrawn for “muzzle-loading.”

It would be desirable to use ultrasound, and particularly endoscopicultrasound (EUS) for navigation and placement of fiducials. As such itwould be desirable to provide and use the largest possible fiducial thatwill provide improved echogenicity based on its size and echogenicprofile. It would be desirable to provide multiple fiducials in a needlethat can be introduced in a controlled serial manner (one, or some otherpre-determined number, at a time) rather than requiring manual reloadingafter placement of each fiducial.

BRIEF SUMMARY

Embodiments of a fiducial deployment system described herein may includeone or more of: one or a plurality of fiducials having one or moreprotuberances, a slotted needle configured for delivering a plurality offiducials in serial fashion where the slot receives the fiducialprotuberances without a detent that occupies any internal diameterneedle lumen portion, a handle configured for controlling the serialdelivery by user-operated deployment of a predetermined number offiducials, and a method of delivering fiducials to a target region.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-1B show a prior art fiducial introducer and method of use;

FIGS. 2A-2C show an embodiment of a fiducial from, respectively, top,side, and transverse section views;

FIG. 3 shows a top view of a slotted needle embodiment;

FIG. 3A shows a top view of another slotted needle embodiment;

FIGS. 4-4B show, respectively, a top perspective view, a longitudinalsection view, and a transverse section view of a distal fiducialdeployment system portion;

FIGS. 5A-5C show a method of placing fiducials;

FIGS. 6A-6B show a handle embodiment for a fiducial deployment systemwith actuation of same;

FIGS. 7 and 7A-7C show, respectively, an assembled handle view and threeactuation method step views, where each actuation method view is showncorresponding with a distal needle of an advancement mechanismembodiment for a fiducial deployment system, with FIG. 7D showing alongitudinal section view of one actuation method step;

FIGS. 8 and 8A-8D show, respectively, an assembled view, a “see-throughview” of FIG. 8, and three actuation method step views, of anadvancement mechanism embodiment for a fiducial deployment system; and

FIGS. 9 and 9A-9D show, respectively, an external view, aninternal-component view, and three method-of-use/function actuation stepviews of an advancement mechanism embodiment for a fiducial deploymentsystem.

DETAILED DESCRIPTION

The terms “proximal” and “distal” are used herein in the common usagesense where they refer respectively to a handle/doctor-end of a deviceor related object and a tool/patient-end of a device or related object.

A variety of fiducial and needle configurations may be used in keepingwith the present embodiments including those described in U.S. Pat. App.Publ. Nos. 2010/0280367; 2011/0152611 to Ducharme et al.; 2013/0006101to McHugo et al.; 2013/0006286 to Lavelle et al.; and 2013/0096427 toMurray et al., each of which is incorporated by reference herein in itsentirety. One embodiment, illustrated with reference to FIGS. 2A-2C, ofa fiducial 400 has a generally columnar body that is generallycylindrical with a generally circular transverse cross-section. Alongitudinal surface face of the body may be dimpled to enhance itsability to reflect ultrasound waves and thereby provide a desirableechogenic profile. This dimpled characteristic may alternatively beembodied as a different irregular, patterned, or textured surfacefeature (e.g., knurled, ribbed) that may enhance the echogenicity of thefiducial 400, which will aid in visualizing it during EUS-guidedplacement, and allow it to be used in ultrasound visualization of atarget site being marked by one or more fiducials 400 (e.g., a tumor).

Such a fiducial 400 preferably will be formed of a radio-opaque,non-ferromagnetic material such as, for example, gold, platinum,palladium, iridium, or alloys thereof, with one preferred embodimentincluding an alloy of palladium with rhenium (advantages of which mayinclude desirable radio-opacity, market-price stability superior togold, and ultrasound-reflectivity/echogenicity due to density). Beingradio-opaque will allow the fiducial to be used in deployment techniquesusing fluoroscopy, as well as making it detectible/visualizable byradiographic means during a treatment or other procedure where it may bedesirable to know the location(s) of one or more fiducials. Beingnon-ferromagnetic will lessen the likelihood that visualizationtechniques or other procedures employing magnetic fields such as, forexample, MRI, will re-orient or otherwise dislodge a fiducial. Echogenicconstruction of a fiducial or needle may be enhanced by surface texture,but can also be provided by structural inclusions such as embeddedbubbles or beads that provide for a different ultrasound reflectivitythan material surrounding them. Fiducials may also be coated with amaterial (e.g., parylene) configured to reduce backscatter duringradiography.

In a preferred embodiment, the fiducial 400 is configured anddimensioned for passage through and release from a needle lumen. For anendoscopic delivery system, the fiducial body 402 (exclusive of theprotuberance) preferably will have an outer diameter (OD) of about thesame or less than the inner diameter (ID) of a needle lumen, but the ODof the fiducial body preferably will be no greater than the needle ID.As used herein, the OD of the fiducial refers to an imaginary circle (orother geometric shape) whose outermost boundaries all fit within the IDof the needle lumen. In other words, it is preferable that the fiducialis dimensioned to fit slidably into the needle lumen, except theprotuberance, which projects into the slot.

The longer body portion distal of the protuberance can help make certainthat, during deployment through a needle, a first fiducial distal ofthis second fiducial will be fully advanced out of the needle beforethat second fiducial is positioned for deployment, as will be madeclearer with reference to FIGS. 7-8B below. Accordingly, in manypreferred embodiments, the fiducial protuberance (of the second andsuccessive fiducials) will be nearer its proximal end than its distalend, so that the distal fiducial body portion projects sufficientlydistally that it will advance the preceding first fiducial completelyout of the needle lumen by the time that the second fiducial is in aposition to be deployed (see FIGS. 4A-4C, 7B, 8B, and correspondingtext). It should be appreciated that, even if all surfaces of thecentral fiducial portion 402 and protuberance 408 are generally smooth,the preferred materials forming the fiducial 400 and the presence of theprotuberance 408 may provide a desirable echogenic profile that isreadily visualizable under ultrasound at a resolution sufficient forlocating and/or navigating it in a patient's body.

The fiducial 400 has a generally cylindrical body 402 formed as a masswith a generally circular transverse cross-section along its proximaland distal end sections. A protuberance 408 projects from thelongitudinal circumferential face 406 of the fiducial body 402. Asviewed from the top, the protuberance 408 is generally obround. Theirregular shape and increased surface area (as compared to a typicalcylindrical fiducial of the type used in plug-ended systems and/orsystems with some type of lumen-occupying detent) preferably enhancesthe echogenicity of the fiducial, which preferably will already bedesirably high due in part to its composition.

The protuberance 408 includes protuberance end faces 407 that mayprovide one or more of chamfered, filleted, and radiused transition tothe outer face 406 of the body 402. The body 402 is generally a rightcylinder, but for the protuberance 408. In this embodiment, theprotuberance 408 is rounded and substantially parallel to thelongitudinal central axis of the fiducial body, and it is about one halfthe length of the body 402, and it is centered along the body length. Ina preferred embodiment, the fiducial 400 is configured and dimensionedfor passage through and release from a needle lumen. For an endoscopicdelivery system, the fiducial body (exclusive of the protuberance) willhave an outer diameter (OD) of about the same or less than the innerdiameter (ID) of a needle lumen, but the fiducial body OD preferablywill be no greater than the needle ID. The protuberance 408 will engageand ride along through a needle slot.

Dimensions of one exemplary embodiment are also described with referenceto FIGS. 2A-2C. In one exemplary embodiment the body 402 is about 0.12inches (3.05 mm) long and has an OD of about 0.034 inches (0.86 mm). Theprotuberance 408 is about 0.06 inches (1.5 mm) long and is aligned alonga midline of the body. The protuberance 408 projects about 0.008 inches(0.2 mm) above the OD of the body 402 and is about 0.011 inches (0.28mm) wide. These measurements and proportions may be varied in otherembodiments while remaining within the scope of the presently-claimedmaterial. For example, the protuberance may be more distally orproximally located, and may be at an angle relative to the midline suchthat it partially spirals around the outer surface of the body.

FIG. 2C shows an end view of a transverse section taken along line 2C-2Cof FIG. 2A. It shows one embodiment of general proportions of a fiducialbody and protuberance of the present system.

FIG. 3 shows an embodiment of a fiducial introduction needle 800. Theneedle 800 is illustrated with a beveled distal tip 802. Its tubularcannula body 804 includes a longitudinal needle slot 806 along a distalend region of the cannula 804. The slot 806 preferably includes at leastone detent including at least one detent surface, and more preferablytwo detents. The slot 806 is shown as being open through the entire wallof the cannula 804, but it should be appreciated that the slot mayextend less than the thickness of the needle wall, such that it isembodied as a groove.

In the embodiment of FIG. 3, the detent is formed as a narrowed portion807 of the slot 806 between two tabs 808. The tabs 808 are generallytrapezoidal, but may have a different geometry in other embodiments. Asshown in FIG. 3A, in certain preferred embodiments, the tabs 808 may belocated immediately adjacent the distal bevel (e.g., to maximizeefficiency of advancing a fiducial past them and out of the needle whileminimizing residual overlap of a deployed fiducial with the beveledportion of the distal needle tip). Each of the transitions between theedge 806 a of the needle slot 806, the proximal tab edge 808 a, centraltab edge 808 b, and distal tab edge 808 c may be cornered (e.g.,chamfered or filleted) or rounded (e.g., radiused). The tabs 808preferably are near the distal end of the slot 806.

The body wall cannula 804 generally circumferentially defines a needlelumen 810 configured to allow sliding passage therethrough of a fiducialsuch as, for example, a fiducial (e.g., as shown in FIGS. 2A-2C orothers that would readily pass through the needle lumen 810, preferablywith controllable retention of the fiducial(s) by the tabs 808). Theneedle may be constructed from a nickel-titanium alloy, cobalt-chromium(CoCr) alloy, stainless steel or any other suitable material. Its tipmay have a different geometry than the beveled configuration shown. Inan alternative embodiment, the tabs 808 may meet such that they will beforced to flex upward and/or outward to a greater degree to allowpassage of a protuberance on a fiducial. And, the outer surface of theneedle may be dimpled or otherwise textured to provide enhancedechogenicity.

An exemplary needle embodiment is also described with reference to FIG.3, which exemplary needle embodiment may be configured and dimensionedfor use with the exemplary fiducial embodiment described above withreference to FIGS. 2A-2C. In one such exemplary needle embodiment, theID of the needle lumen is at least about 0.034 inches (0.86 mm). The ODof the needle is about 0.042 inches (1.07 mm; about 19-gauge), with awall-thickness of about 0.008 inches (0.2 mm). The slot portion proximalof the tabs is about 0.02 inches (0.5 mm) wide and about 0.42 inches(about 10.7 mm) long. Each of the tabs extends about 0.06 inches (0.15mm) out of the slot edge and has a slot-facing edge that is about 0.02inches (0.5 mm) long (not including the proximal and distal angledtransitions from the slot edge, which are radiused at about 0.005 inches(0.13 mm)). These measurements and proportions may be varied in otherembodiments, including those illustrated herein, while remaining withinthe scope of the presently-claimed material. For example, the particulardimensions of a slot, tabs, and fiducial may be configured for use witha 22-gauge needle having a desirable balance of flexibility andstiffness, as well as including a distal needle tip bevel of about 30°,a slot width of about 0.014 inches (about 0.36 mm) with slot tabsseparated only by about 0.006 inches (about 0.15 mm) across the slot,and echogenicity-enhancing surface dimpling disposed along the needleexterior adjacent and generally parallel with at least a distal lengthof the slot.

The distal end portion of a fiducial deployment system 1000 is describedwith reference to FIG. 4, which is an external view, FIG. 4A which is alongitudinal section view taken along line 4A-4A of FIG. 4, using theneedle 800 and fiducial 400 described above, and FIG. 4B, which shows atransverse section view along line 4B-4B of FIG. 4A. The system 1000includes a flexible elongate needle sheath 1002. The needle 800,including a more flexible proximal body portion 820 extends through asheath lumen 1004. At least one fiducial 400, illustrated here as aplurality of fiducials 400, is disposed slidably removably in a distalregion of the needle lumen 810 of the needle's cannular body. Thecentral longitudinal body portion 402 substantially occupies the innerdiameter of the needle lumen 810. The protuberance 408 of each fiducial400 has a height that may be about the same as the thickness of theneedle wall, including the slot 806 into which the protuberances 408project.

The protuberance 408 of the distal-most fiducial 400 is captured againstthe tabs 808 of the needle 800. A stylet 1006 configured for use as apusher is disposed through a portion of the needle lumen 810 andpreferably is configured for actuation from the proximal end, whereby itcan be used to distally advance/push out the fiducials and/or hold themin place as the needle is withdrawn from around them. The presence ofthe fiducials and stylet in the needle 800 preferably improve itscolumnar strength reduce the likelihood that it will get bent, crimped,or otherwise damaged as it is navigated through and out of the distalend of an endoscope working channel (not shown).

FIG. 4B shows a transverse section end view of a section of a needle 800(as in FIG. 3) and a fiducial 400 (as in FIGS. 2A-2C). This view showsthe preferred close tolerances and a preferred orientation of thefiducial body relative to the needle lumen 810 and the protuberance 408relative to the needle slot 806.

Several different handle embodiments may be used to effect advancementand release of one or more fiducials. Certain handle embodiments aredescribed with reference to FIGS. 7A-8B below, including with referenceto the structure and method described below with reference to FIGS. 4-4Band 5A-5C.

A method of using the fiducial deployment needle of FIGS. 4-4B isdescribed with reference to FIGS. 5A-5C, with reference to thestructures shown in greater detail in FIGS. 4-4B. In a preferred methodof use, an endoscope 1100 is provided, including a working channel 1102.In one preferred method, the endoscope is an EUS endoscope including adistal ultrasound array 1104 configured for ultrasound imaging. Theendoscope 1100 preferably also includes a video element 1106 (e.g., CCD,optical camera, or other means for optical visualization). The methodsbelow are described with reference to placing fiducials 400 at themargins of a tumor 1152 of a patient's pancreas 1150, such that theneedle body will be of sufficient length and navigability (e.g.,pushability and flexibility) to perorally be directed through apatient's gastrointestinal tract to a target site, including doing sovia a working channel of an endoscope such as a gastric endoscope,colonoscope, anuscope, or other visualization/procedure-assistingdevice.

The endoscope 1100 is shown in FIG. 5A as having been directed through apatient's duodenum 1140 until its distal end portion is adjacent theSphincter of Oddi 1142, which provides access to the common bile duct1144 from which the pancreatic duct 1146 branches and leads to thepancreas 1150.

As shown in FIG. 5A, the sheath 1002 has been advanced to the duodenalwall and the needle 800 has been pierced therethrough, extending nearthe pancreatic duct 1146 to a location adjacent the tumor 1152 in thepancreas 1150. As shown in FIG. 5B, the needle 800 is directed to afirst target site at a margin of the tumor 1152 (preferably underultrasound guidance, which can be replaced, complemented, and/orverified by fluoroscopy or another visualization technique). Once thedistal end 802 of the needle 800 is positioned at the first target, thedistal-most fiducial 400 therein is deployed. In one aspect, thedeployment may be accomplished by positioning the distal needle end 802and the fiducial 400 therein at the first target, then retracting theneedle 800 while retaining the position of the stylet 1006 such that thefiducial 400 remains in the desired first target position. In anotheraspect, the deployment may be accomplished by positioning the distalneedle end 802 and the fiducial 400 therein adjacent the first target,then holding the needle 800 in position while advancing the stylet 1006such that the fiducial 400 is advanced into the desired first targetposition.

As will be appreciated from the structure of the needle 800 andfiducials 400 as shown in FIGS. 4-4B, a user preferably will be able tocontrol advancement/deployment of the fiducials to one at a time, suchthat a plurality of fiducials (without any spacers) may serially—butseparately and independently—directed into different locations. Then thefiducial 400 is in a “ready to deploy” position, its distal protuberanceface 408 a is engaged against the proximal tab edges 808 a. To deploythe fiducial 400, the user must move one of the stylet 1006 or needle800 relative to the other with sufficient force to advance theprotuberance 408 through the tabs 808.

The user preferably will have a tactile sense of resistance as theprotuberance 408 passes through the tabs 808, which resistance willdecrease immediately as soon as the protuberance clears the tabs. Thenthe user preferably continues the relative motion of stylet and needleuntil resistance is again encountered, indicating that the next fiducialbehind the distal-most one has met the proximal tab edges 808 a.

It will often be preferred that the fiducials (and the protuberancesthereon) be proportioned such that complete deployment of a distal-mostfiducial includes it substantially clearing the distal needle tip 802and coincides with the protuberance of the next distal-most fiducialmeeting the proximal tab edges 808 a. As such, it may be advantageous insome fiducial embodiments to position the protuberance more proximallyon the fiducial body such that a fiducial body portion distal of theprotuberance is longer than a body portion proximal of the protuberance.It should be appreciated that the protuberance of almost any fiducialembodiment in keeping with principles of the present invention may bedisposed near the proximal end up to and including flush with theproximal end of the fiducial body). FIG. 5C shows the fiducial in place,with the needle withdrawn away from it.

Next, the user may retract the needle 800 into the sheath 1002 to asufficient distance allowing it to be re-extended to a second targetsite, where the procedure described above may be repeated. These stepsmay be repeated for placement of third, fourth, and further fiducials.As is known in the art, these fiducials may be used for “positivetargeting” and/or “negative targeting” of a therapy such as radiationtherapy (“positive targeting” indicating “treat here”, and “negativetargeting” indicating “do not treat here”). The present system presentsnumerous advantages. For example, consider a patient already undergoingan endoscopy procedure to biopsy a located but undiagnosed tissue mass.The endoscopic biopsy can be taken and a tissue slide preparedimmediately. If a diagnosis is made (in conjunction with whatever otherdata are available and pertinent) that the tissue mass will benefit froma treatment where placement of fiducials is indicated, the physician canimmediately deploy fiducials in the manner described above.

The ability to complete the method using direct/video and ultrasoundimaging with little or no use of fluoroscopy presents an advantage ofminimizing the radiation exposure of the patient (who may, for example,have to undergo radiation therapies where the total amount of exposureto radiation is desired to be minimized to that which is therapeuticallyand diagnostically necessary). Advantages of time and expense for thepatient, physician and other treating/diagnostic personnel, and thetreatment facility are likely as implementation of the present methodmay prevent all of those entities from having to schedule and conduct asecond endoscopic procedure, and/or to extend the initial diagnosticprocedure with the time-consuming methods and materials currentlyavailable in the prior art as described. It should also be appreciatedthat, when informed by the present disclosure, those of skill in the artmay utilize and/or adapt the presently-disclosed embodiments forpercutaneous use while remaining within the scope of one or more claims.

Fiducials with generally cylindrical or otherwise generally regulargeometry may migrate after having been placed in a desired location,including that—over the course of multiple treatments of a target areadelineated by fiducials—they may migrate with changes in the conditionof surrounding tissues. For circumstances where it may be advantageousto minimize migration, a fiducial may be used that includes one or moreanchoring projections.

FIGS. 6A-6B show a handle embodiment 1600 that may be used with afiducial deployment system. The handle 1600 includes a sheath-attachedhandle member 1602 with a needle-attached handle member 1604longitudinally slidably disposed on its proximal end. A handle member1606 (which may be configured for scope-attachment) is slidably attachedto the distal end of the sheath-attached handle member 1602. Thesheath-attached handle member 1602 is attached to the needle sheath 1612and the needle-attached handle member 1604 is attached to the needle1614 (which may be configured in the manner of any of the needlesdisclosed herein or later developed in accordance with principles of thepresent disclosure). The scope-attachment handle member 1606 isconfigured for incrementally fixable, longitudinally-adjustable(relative to the other handle components) attachment to the exterior ofan endoscope working channel (not shown) using, for example, a threadedcavity 1616. The scope-attachment handle member 1606 allows a user todetermine the distance by which the sheath 1612 will extend from astandard-length endoscope, and it may include numerical or other indicia1617 corresponding to that relative length and an adjustable engagementstructure 1618 allowing a user to select a length and engage thescope-attachment handle member 1606 accordingly. It should beappreciated that embodiments of the handle described and claimed hereinmay be practiced within the scope of the present invention withoutincluding a scope-attachment member.

The sheath-attached handle member 1602 includes numerical indicia 1608and an adjustable ring 1609 that limits the movement of theneedle-attached handle member 1604 and provides a way to select thedistance to which the needle 1614 may be extended beyond the sheath1612. By way of illustration, the configuration shown in FIG. 6A wouldallow the sheath to extend 5 units (e.g., inches, cm) beyond the distalend opening of an endoscope working channel, and the needle 1614 wouldnot extend at all beyond the distal end of the sheath 1612. Theconfiguration shown in FIG. 6A would allow the sheath to extend 3 units(e.g., inches, cm) beyond the distal end opening of an endoscope workingchannel, and the needle 1614 would be allowed to extend up to 6 unitsbeyond the distal end of the sheath 1612, although its current positionwould be only about 4 units beyond the distal end of the sheath 1612.

A stylet 1610 extends through a lumen of the needle 1614 and has astylet cap 1611 fixed on its proximal end. The stylet 1610 is shown asbeing retracted proximally in FIG. 6A, and extended beyond the distalend of the needle 1614 in FIG. 6B. The stylet 1610 may be manuallyadvanced distally through the needle lumen in the same manner asdescribed above (with reference to FIGS. 4-4B) for a stylet 1006. Assuch, a user may use the stylet to manually push fiducials out of adistal end of the needle 1614. If this method is used (e.g., in themanner described above for deployment of fiducials with reference toFIGS. 4-5C), a user may rely upon tactile feedback to determine when afiducial has been advanced beyond any detents, which may be difficultthrough a long stylet—particularly if the detents are rounded such thatthe advancing motion is relatively smooth. Accordingly, it may beadvantageous to provide an advancement mechanism configured to attach to(including being integrated with) the handle 1600 that provides improvedcontrol of stylet advancement.

FIGS. 7-9D show embodiments of advancement mechanisms that may be usedwith handle assembly configurations similar to those of FIGS. 6A-6B, orother handle configurations (including, for example, those disclosed inU.S. Pat. App. Publ. Nos. 2010/0280367; 2011/0152611 to Ducharme et al.;2013/0006101 to McHugo et al.; 2013/0006286 to Lavelle et al.; and2013/0096427 to Murray et al. FIGS. 7-7C and 7D show a first ratchetedhandle component 1750 for a fiducial deployment system. In this andother embodiments, the first ratcheted component 1750 may be removablyor permanently attached to a proximal end 1605 of a handle such as theone shown in FIGS. 6A-6B, where it will provide means for controlledadvancement of a stylet (e.g., stylet 1610) in lieu of direct and/ormanual manipulation of the stylet cap 1611.

The first ratcheted handle component 1750 may include at least oneactuation member 1770 embodied as a slider and an elongate first handlemember body 1754 that includes and defines a central longitudinal axisand a handle lumen. It may be attached directly or indirectly to acannula (e.g., needle and/or sheath), such as via an elongate distalouter body having a longitudinal body lumen (e.g., in some embodiments,needle-attached handle member 1604, or—in other embodiments—a fiducialneedle and/or sheath). A stylet 1760 (which may correspond to the stylet1610) extends through at least a portion of the first handle member 1754along or generally aligned with its central longitudinal axis.

A rack member 1762 is attached to the proximal stylet end and islongitudinally movably disposed in the lumen of the handle member body1754. The central rack member 1762 includes a plurality oflaterally-protruding ratchet teeth 1763, which are—in this embodimentdisposed longitudinally aligned along opposite sides of the rack member.The actuation members—embodied here as two opposed sliders 1770—are eachdisposed longitudinally slidably in the lumen of the handle member 1754.A user-operable portion of each slider 1770 extends through an aperture1755 through the handle member wall 1754. The sliders 1770 are biased orurged toward the proximal end by compression coil springs, but those ofskill in the art will appreciate that this proximal-directed tendencymay be accomplished by a variety of means without exceeding the scope ofthe present disclosure. The length of the aperture 1755 limits theproximal/distal movement of the sliders 1770, and is dimensioned tocorrespond to the desired increment of stylet advancement.

As shown in FIGS. 7A-7C, the sliders each include a tooth-engagementportion 1770 a that extends between adjacent ratchet teeth 1763 on therack 1762. These figures also show numerical indicia 1764 on the rack1762, which are visible to a user through a window 1765 in the handlebody wall 1754. These indicia (which in other embodiments may be coloredbands or other visual indicia) may be used to provide a user withinformation about the distance advanced by the stylet's distal end fromactuation of the sliders 1770. In a fiducial-deployment needle, ascontemplated here, the number shown through the window 1765 may indicatethe number of fiducials that have been deployed (as the indicia will bespaced apart to correspond with a stylet length advanced to deploy oneor another predetermined number of fiducials at/near the distal endregion 1714 of an attached fiducial needle, e.g., within a patientbody). The rack 1762 may be urged or biased proximally by a spring orother means, a keeper pawl or other keeper structure may be provided(e.g., projecting inward from the handle body wall 1754 in the manner ofkeeper 1968 below), and/or friction between the stylet and a distalcannula (e.g., needle, sheath, catheter) length may be sufficient, eachto prevent retrograde (i.e., proximal) movement of the stylet and rack.

FIGS. 7A-7C show a distal advancement of the rack 1762 and stylet,corresponding to a fiducial-deployment or other distal stylet movementaction as shown in an exemplary distal needle view of FIG. 7C (see also,e.g., FIGS. 5B-5C). The longitudinal portion (parallel with the rack) ofthe sliders may be flexible enough to allow the tooth-engagement portion1770 a of the sliders 1770 to bend out of engagement with the teeth1763. However, one preferred embodiment includes the teeth 1763 beinghinged or otherwise retractable and/or depressible (recessible) into therack 1762, means for which will readily be appreciable by those of skillin the art with reference to the present specification.

This is illustrated with reference to FIG. 7D, showing a longitudinalsection view of the rack 1762 in a state during rack-advancement wherethe teeth 1763 depress, fold back, or are otherwise retractedresiliently into the rack body (e.g., as would occur between the viewsshown in FIGS. 7B and 7C). The base of each tooth is flexibly attachedto the elongate portion of the rack, allowing reciprocal flexing,folding, depression, or the like, with the teeth being biased to thedefault position shown in FIGS. 7A-7C. Those of skill in the art willappreciate that this can readily be accomplished with polymer and/ormemory-metal construction of the rack and teeth, or with otherappropriate materials. In this manner, the rack 1762 and/or sliders 1770are configured to provide unidirectional distal movement of the stylet1760. The sliders 1770 move reciprocally longitudinally, and the rack1762 moves distally in a series of discrete predetermined incrementsthat preferably correspond to the distance of stylet movement todeploy/dispense one or some other predetermined number of fiducials.Those of skill in the art will also appreciate with reference to FIGS.7A-7D and general knowledge of the state of the art that the springs (noreference number) engaged into the distal ends of the sliders 1770 mayoperate in two different ways: (i) the springs being urged/biasedproximally (“expansion biased”), so that the resting/default position ofthe sliders 1770 is against the proximal end of the apertures 1755 andthe sliders 1755 are actuated by distalward movement to deploy afiducial 400; or (ii) the springs being urged/biased distally(“compression biased”), so that the resting/default position of thesliders 1770 is against the distal end of the apertures 1755 and thesliders 1755 are actuated by proximal slider retraction followed byspring-impelled distalward movement of the sliders against the rack 1762to deploy a fiducial 400.

FIG. 8 shows an external view of a second ratcheted handle component1850 for a fiducial deployment system. In this and other embodiments,the second ratcheted component 1850 may be removably or permanentlyattached to a proximal end 1605 of a handle such as the one shown inFIGS. 6A-6B, where it will provide means for controlled advancement of astylet (e.g., stylet 1610) in lieu of direct and/or manual manipulationof the stylet cap 1611. FIGS. 8A-8D show a longitudinal view of internalcomponents, including a method of operation for this embodiment.

The second ratcheted handle component 1850 may include at least oneactuation member 1870 embodied as a slider and an elongate first handlemember body 1854 that includes and defines a central longitudinal axisand a handle lumen. It may be attached directly or indirectly to acannula (e.g., needle and/or sheath), such as via an elongate distalouter body having a longitudinal body lumen (e.g., in some embodiments,needle-attached handle member 1604, or—in other embodiments—a fiducialneedle and/or sheath). A stylet 1860 (which may correspond to the stylet1610) extends through at least a distal portion of the first handlemember 1854 along or generally aligned with its central longitudinalaxis.

A rack member 1862 is attached to the proximal stylet end and islongitudinally movably disposed in the lumen of the handle member body1854. The central rack member 1862 includes a plurality oflaterally-protruding ratchet teeth 1863, which are—in this embodimentdisposed longitudinally aligned along opposite sides of the rack member.The actuation members—embodied here as two opposed sliders 1870—aredisposed longitudinally slidably through a wall of the handle member1854. The sliders 1870 are biased or urged toward the proximal end bycompression coil springs, but those of skill in the art will appreciatethat this proximal-directed tendency may be accomplished by a variety ofmeans without exceeding the scope of the present disclosure.

As shown in FIGS. 8-8D, the sliders each include an actuatabletooth-engagement button 1897 that extends reciprocatingly betweenadjacent ratchet teeth 1863 on the rack 1862. Each button 1897 isdisposed through a user-operable portion of the slider 1870 that extendsthrough an aperture 1855 through the handle member wall 1854. The lengthof the aperture 1855 limits the proximal/distal movement of the sliders1870, and is dimensioned to correspond to the desired increment ofstylet advancement.

FIGS. 8-8D also show numerical indicia 1864 on the rack 1862, which arevisible to a user through a window 1865 in the handle body wall 1854.These indicia (which in other embodiments may be colored bands or othervisual indicia) may be used to provide a user with information about thedistance advanced by the stylet's distal end from actuation of thesliders 1870. In a fiducial-deployment needle, as contemplated here, thenumber shown through the window 1865 may indicate the number offiducials that have been deployed (as the indicia will be spaced apartto correspond with a stylet length advanced to deploy one or anotherpredetermined number of fiducials at the distal end of an attachedfiducial needle, e.g., within a patient body). In other embodimentsdisclosed here or practiced within the scope of the present disclosure,the indicia may show a length/distance (e.g., in cm, percentage ofstylet length, or other absolute or relative units), or some othermeaningful data. The rack 1862 may be urged or biased distally by aspring or other means, a keeper pawl may be provided, and/or frictionbetween the stylet and a distal cannula (e.g., needle, sheath, catheter)length may be sufficient, each to prevent undesired retrograde (i.e.,proximal) movement of the stylet and rack.

FIGS. 8A-8D show steps of a method for distal advancement of the rack1862 and stylet 1860, corresponding to a fiducial-deployment or otherdistal stylet movement action (see, e.g., the distal needle end andfiducial deployment shown in FIGS. 5B-5C). As shown in FIG. 8A, thebuttons 1897 are biased or urged inward—that is toward, but generallytransverse to—the longitudinal axis. In their default position, thebuttons 1897 are engaged between and against a proximal face of opposedteeth 1863. A user may advance the sliders 1870 distally to contact thedistal end of the aperture 1855, such that the buttons' engagement ofthe teeth 1863 advances the rack 1862 and stylet distally by the desiredincrement. Then, as shown in FIG. 8B-8C, the buttons may be released bythe user and the sliders may be moved (or they will move by beingspring-urged) back proximally. As this occurs, the buttons 1897 will beallowed to reciprocate outward away from the longitudinal axis to passover the next pair of opposed teeth, behind/proximal of which thebuttons will engage (as shown in FIG. 8D) for a potential nextactuation.

Stated differently, the sliders 1870 are actuated to movelongitudinally, and the buttons engage the teeth so that the rack 1862moves distally. This may be done reciprocatingly in a series of discretepredetermined increments that preferably correspond to the distance ofstylet movement to deploy/dispense one or some other predeterminednumber of fiducials.

FIGS. 9-9D show a third ratcheted handle embodiment including a handlecomponent 1950 for a fiducial deployment system. In this and otherembodiments, the ratcheted component 1950 may be removably orpermanently attached to a proximal end 1605 of a handle such as the oneshown in FIGS. 6A-6B, where it will provide means for controlledadvancement of a stylet (e.g., stylet 1610) in lieu of direct and/ormanual manipulation of the stylet cap 1611. FIG. 9 shows an externalview of the handle component 1950 in such an assembly. FIGS. 9A-9D showa longitudinal view of internal components, including a method ofoperation for this embodiment.

As shown in FIGS. 9 and 9A, the handle component 1950 may include anactuation member configured as a depressible button 1970. The button1970 is disposed reciprocatingly/depressibly through the wall of anelongate first handle member body 1954 that includes and defines acentral longitudinal axis and a handle lumen. The handle body 1954 maybe attached directly or indirectly to a cannula (e.g., needle and/orsheath), such as via an elongate distal outer body having a longitudinalbody lumen (e.g., in some embodiments, needle-attached handle member1604, or—in other embodiments—a fiducial needle and/or sheath). A stylet1960 (which may correspond to the stylet 1610) extends through at leasta distal portion of the first handle member 1954 along or generallyaligned with its central longitudinal axis.

A rack member 1962 is attached to the proximal stylet end and islongitudinally movably disposed in the lumen of the handle member body1954. The central rack member 1962 includes a plurality oflaterally-protruding ratchet teeth 1963, which are—in this embodimentdisposed longitudinally aligned along a single side of the rack member1962. The actuation member—embodied here as the button 1970—is disposedgenerally transversely through a wall of the handle member 1954 in amanner contacting a face of at least one of the plurality of ratchetteeth 1963. The depressible button 1970 is biased or urged (e.g., by aspring or other means) away from and transverse to the handlelongitudinal axis.

As shown in FIGS. 9A-9D, the rack 1962 is urged or biased distally by aspring 1969 or other means. A keeper element 1968 prevents the distalmovement of the rack by engaging a distalmost protruding/non-depressedtooth 1963 of the rack 1962. The teeth are depressible into the rack, asshown in the progression of FIGS. 9B-9D. The keeper element 1968 isembodied here by a protrusion of the inner surface of the handle wall1954. The rack 1962 and the lumen formed within the handle are bothgenerally cylindrical with the outer diameter of the rack (excepting theprotruding teeth) being about the same or only slightly less than theinner diameter of the handle 1954 (excepting a recessed track 1967 alongwhich the non-depressed ratchet teeth 1963 are afforded longitudinalpassage). The keeper 1968 is formed by a distal end of the recessedtrack 1967. In other embodiments, the keeper may be embodied as anindentation along the inner handle wall, where only one or somesub-plurality of ratchet teeth are non-depressed, and the distalmost oneengages the wall, while all teeth proximal or distal of theindentation/keeper region are depressed by contact with the innerdiameter of the handle wall.

With this structure disclosed, those of skill in the art will appreciatea method of use. As shown in FIG. 9B, the button 1970 may be actuatedand depressed against a distalmost non-depressed tooth 1963, which (asshown in FIG. 9C) will depress the tooth, disengaging it from retrainingcontact with the keeper 1968. Thus relieved, the rack-urging spring 1969advances the rack distally until the next distalmost, non-depressedtooth stoppingly contacts the keeper 1968, as shown in FIG. 9D.Thereafter the procedure may be repeated. The distance betweenkeeper-engaging surfaces of successive teeth 1963 preferably isdimensioned to correspond to the desired increment of stylet advancement(e.g., for distal deployment of one or a predetermined number offiducials).

As with the foregoing embodiments, a handle window and numerical orother indicia (not shown) may be provided to show the increment ordegree to which the rack has been advanced. Those of skill in the artwill appreciate that actuation may user-perceptibly be indexed by visualindicia, tactile indicia, audible indicia, or any combination thereof,and that the indicia may be configured to correspond to a pre-determinedlongitudinal movement distance of the stylet by the rack(s). A varietyof such indicia are known and well within the skill in the art, giventhe present disclosure.

Those of skill in the art will appreciate with reference to theembodiments disclosed above that a predetermined number of fiducials maybe released into a desired location by a single actuation of the lever,button, or other actuation member. The predetermined number preferablywill be one, but may include a plurality of fiducials. The configurationof the present embodiments provide clear advantages over prior designsthat utilize releasable end-plugs in a needle to retain fiducials,and/or that use less refined means of controlling the fiducial releasethan the notch/tab needle design and/or actuation handles describedherein.

Drawings and particular features in the figures illustrating variousembodiments are not necessarily to scale. Some drawings may have certaindetails magnified for emphasis, and any different numbers or proportionsof parts should not be read as limiting, unless so-designated by one ormore claims. Those of skill in the art will appreciate that embodimentsnot expressly illustrated herein may be practiced within the scope ofthe present invention, including that features described herein fordifferent embodiments may be combined with each other and/or withcurrently-known or future-developed technologies while remaining withinthe scope of the claims presented here. For example, a needle andfiducials of the present system may be used percutaneously, including inanother minimally invasive surgical procedure, such as alaparoscopic-type procedure, within the scope of the claimed invention.For example, a target site may be a location in or near thegastrointestinal tract (e.g., liver, pancreas) such as those locationsthat may be accessible by endoscopy (using a minimally invasiveendoscope introduced through a natural patient orifice, e.g., mouth,anus, vagina). This includes—more broadly—sites reachable through NOTES(natural orifice translumenal endoscopic surgery) procedures. Thepresent method and device may also be used with other minimally-invasivesurgical techniques such as percutaneous endoscopic procedures (e.g.,laparoscopic procedures) or percutaneous non-endoscopic procedures, butmost preferably is used with less invasive endoscopy procedures. It istherefore intended that the foregoing detailed description be regardedas illustrative rather than limiting. And, it should be understood thatthe following claims, including all equivalents, are intended to definethe spirit and scope of this invention.

We claim:
 1. A medical device handle configured for controlled incremental lengthwise stylet advancement through a cannula, the handle comprising: an elongate outer handle body defining a longitudinal handle lumen; an elongate cannula attached directly or indirectly to a distal end of the handle body, the cannula defining a longitudinal cannula lumen in mechanical communication with the handle lumen; a rack member, including a plurality of longitudinally-aligned, laterally protruding and depressible, retractable, and/or foldable teeth, where the rack member is disposed within the handle lumen; a stylet extending distally from the rack member into the cannula lumen; and a pair of actuation members with a portion of the actuation members engaging against one of or between two or more of the plurality of teeth, where actuating of the actuation members by moving the actuation members longitudinally relative to the handle along a handle slot of predetermined length is effective to move the rack member distally by a predetermined lengthwise increment.
 2. The medical device handle of claim 1, where the predetermined lengthwise increment corresponds to a length of a fiducial.
 3. The medical device handle of claim 1, where the actuation members are urged proximally.
 4. The medical device handle of claim 1, where the rack member includes indicia, viewable through a window in the handle member, of a number of fiducials deployed by distalward movement of the rack member relative to the cannula.
 5. The medical device handle of claim 1, where the actuation members are configured as generally symmetrical sliders.
 6. The medical device handle of claim 1, where the rack member and the elongate outer handle body each are generally cylindrical with an outer diameter of the rack member—exclusive of the teeth—about the same or slightly less than an inner diameter of the handle lumen, and where the inner diameter of the handle lumen includes a recessed track allowing longitudinal movement of teeth of the rack member, and a portion of the recessed track comprises a keeper element.
 7. The medical device handle of claim 1, where the rack member teeth, the actuation members, or both, are configured for unidirectional distal rack-advancing engagement when the actuation members are moved distally, and are configured to allow non-rack-moving proximal reciprocation of the actuation members from a proximal handle slot end toward a distal handle slot end.
 8. The medical device handle of claim 1, where the rack member teeth flex out of a longitudinal linear axis in toward a longitudinal central axis of the rack member when contacted by the actuation members.
 9. The medical device handle of claim 1, where the rack member is generally longitudinally hollow along at least a lengthwise portion including the rack member teeth.
 10. The medical device handle of claim 1, where the rack member teeth each is generally shaped as a right triangle.
 11. The medical device handle of claim 1, where the base of each rack member tooth is flexibly attached to an elongate portion of the rack member, providing for reciprocal flexing, folding, or depression, with the teeth being biased to a default position aligned with a longitudinal axis of the rack member. 